How to find the starting winding of the refrigerator compressor yourself: 3 proven methods

When the refrigerator refuses to start, but the hum of the compressor is heard, the problem often lies in starting winding or related elements. This malfunction occurs in 60% of cases of breakdowns of compressors of household refrigerators of the Atlant, Indesit, Samsung and Liebherrbrands. However, before replacing parts or calling a technician, it is necessary to accurately identify the starting winding - without this it is impossible to check its functionality or connect an external starting relay.

In this article you will find three working methods searching for the starting winding (including visual inspection, resistance measurement and circuit analysis), and also learn how to distinguish it from the working winding and the common output. We will analyze the nuances for different types of compressors - from classic Danfoss to inverter models Mitsubishi. Important: all manipulations with electricity require compliance with safety precautions, which are described in detail in the corresponding section.

Why it is important to correctly identify the starting winding

The starting winding in a refrigerator compressor plays a key role: it creates the initial rotor torque in the first seconds of startup. Without it, the engine either does not start at all or overheats, which leads to operation thermal relay (click when turning off). Errors in determining the windings are fraught with:

• 🔥 Winding burnout if the starting capacitor is connected incorrectly (especially important for compressors Embraco with high starting current).
• ⚡ Short circuit, if you confuse the common terminal with the starting terminal when testing with a multimeter.
• 💸 Unnecessary replacement of the compressorwhen the problem was in the relay or capacitor, and not in the windings.

In practice, craftsmen are faced with two typical scenarios: either the starting winding has a break (resistance tends to infinity)or its insulation is broken into the housing (the resistance between the terminal and the metal housing of the compressor is less than 2 MOhm). In both cases, accurate diagnostics are required, starting with identification of the terminals.

Method 1: Visual inspection of the compressor and its terminals

Let's start with the simplest method, which does not require tools. Most refrigerator compressors (for example Secop or LG Inverter) have standard terminal markings. A typical pinout looks like this:

• S (Start) - starting winding.
• R (Run) - working winding.
• C (Common) - general output.

However, in practice, the markings may be missing or erased. In this case, pay attention to:

• 🔧 Terminal location: on most compressors, the starting winding (S) is located left, when looking at the terminal block from above (for models Danfoss NL/NM).
• 📏 Contact size: the common terminal (C) often has a larger diameter terminal (4-5 mm versus 2-3 mm for S i R).
• 🎨 Wire insulation color (if the compressor new):
  • Red/orange - starting winding.
  • Black/brown - working winding.
  • White/yellow - general terminal.

Exceptions from marking rules

On compressors Embraco EG/EM terminals can be marked as T (general), P (starting), M (working). data-i="103">In inverter models, the terminals are often hidden under a plastic cover, and their markings are applied to a sticker on the side. Mitsubishi In inverter models, the terminals are often hidden under a plastic cover, and their markings are applied to a sticker on the side.

If it was not possible to visually identify the windings, proceed to the next method - resistance measurement.

Method 2: Checking with a multimeter (resistance measurement)

This is the most reliable method, requiring a minimum set of tools: a multimeter (even a budget model is suitable DT-830B) and a screwdriver for unscrewing the terminals. Algorithm of actions:

1. Disconnect the refrigerator from the network and discharge the capacitor (by short-circuiting its terminals with an insulated screwdriver). handle).
2. Remove the plastic cover from the compressor terminal block.
3. Disconnect all wires from the terminals (take a photo of their location in advance!).
4. Switch the multimeter to resistance measurement mode (200 Ohm range).

Now measure the resistance between all pairs of terminals. Typical values for compressors with a power of 100-150 W:

Key point: the resistance of the starting winding (S → C) is always greater than the resistance of the working winding (R → C)If the values are the same or opposite, you have found it. the wrong pair of terminals. Also check for a short to body: the resistance between any terminal and the metal body of the compressor should be greater than 2 MOhm (use the 20 MOhm range on the multimeter).

Turn off the power and discharge the capacitor|

Remove the terminal block cover|

Disconnect all wires (take a photo of the location)|

Measure the resistance between all pairs of terminals|

Compare the values with a standard table|

Ring the case (2 MOhm and higher)

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Method 3: Analysis of the compressor connection diagram

If the first two methods do not produce results (for example, there is no marking on the compressor and the winding resistances do not correspond to the standard table), analysis of the electrical diagram will help. It is usually located:

• 📄 On the sticker on the back of the refrigerator. (for models Beko, Bosch).
• 🔧 Under the plastic cover of the starting relay (for Atlant, Stinol).
• 🖥️ In the operating instructions (section "Electrical diagram").

In the diagram, the windings are designated as follows:

• S or Start — launcher.
• M, Run or Main —working.
• C or Com —general output.

Pay attention to the connection starting relay and capacitor:

• The starting relay is always connected to S and C.
• Working capacitor (if any) - between S and R.

By tracing the wires from the relay to the compressor terminals, you will accurately identify the starting winding.

Features of inverter compressors

In models with inverter control (for example, Samsung Digital Inverter) the starting winding may be missing - instead, an electronic control unit is used. In this case, diagnostics are carried out through the service menu or using a specialized tester (for example, Refco CCT-3000).

Typical mistakes when searching for a starting winding

Even experienced technicians sometimes make mistakes that lead to incorrect diagnostics. Here are the most common ones. common:

1. Ignoring the common terminal: many people forget that the resistance between S and R is the sum of the resistances of both windings. If you do not take into account the common terminal (C), you can incorrectly interpret the multimeter readings.
2. Check under voltage: measuring the resistance of the windings without disconnecting the compressor from the network is dangerous - this leads to damage to the multimeter or electric shock.
3. Confusion with the capacitor: the starting capacitor (if external) is often connected in parallel with the starting winding. If you do not disconnect it before measurements, the multimeter will show incorrect values.

Another common problem is ignoring the compressor temperature. The resistance of the windings depends on temperature: for a cold compressor it can be 10–15% lower than for a heated one. Therefore, for accurate measurements, allow the compressor to cool to room temperature (2-3 hours after shutting down).

What to do if the starting winding is faulty

If the diagnostics showed a break or short circuit in the starting winding, you have three options:

1. Replacement of the compressor —the most reliable, but expensive method (the cost of a new compressor for Indesit or Atlant — 8–15 thousand rubles). Justified if the refrigerator is older than 10 years.
2. Rewinding windings is cheaper (3-6 thousand rubles), but requires specialized equipment. Suitable for rare models of compressors (for example, Copeland ZR).
3. Installing an external starting device are used. is a temporary solution for compressors with a partially working winding. Blocks like Supco SPP6 or 3-in-1 Hard Start Kit.

To temporarily restore functionality, you can use a starting relay with protection. overheating (for example, Danfoss 103N0010It will automatically turn off the compressor at a critical current, preventing burnout of the windings. However, this will not completely solve the problem - over time, the malfunction will appear again.

Safety precautions when working with the compressor

Working with the electrical circuits of the refrigerator requires compliance with measures. precautions. Basic rules:

• ⚡ Disconnect the refrigerator from the mains before any manipulations with the compressor. Do not rely on the switched off thermostat - it does not break the power circuit!
• 🧤 Use dielectric gloves and tools with insulated handles (insulation class not lower than 1000 V).
• 🔌 Discharge capacitors before work: even after turning off the power, they can store a charge of up to 300 V.
• 🌡️ Do not touch the compressor housing immediately after turning off - it can be heated to 80–90°C.

Take special care when working with inverter compressors. Their electronic boards are sensitive to static electricity. Only touch the board contacts with a grounded soldering iron or antistatic tweezers.

FAQ: Frequently asked questions about compressor starting windings

Is it possible to start a compressor without a starting winding?

Technically, yes, but only manually. spin the compressor shaft with an external drive (for example, a drill with a rubber attachment) to operating speed (1500–3000 rpm). However, this is a temporary solution - the next time you start the problem, the problem will repeat. In industrial conditions, they use phase shifting devicesfor such cases, but in everyday life this is not practical.

How to check the starting capacitor?

Disconnect the capacitor from the circuit and check it with a multimeter in capacitance measurement mode (range 10–100 µF) The normal capacitance value is usually indicated on the capacitor body (for example, 35 ± 5 µF). Also check the resistance between the terminals: it should gradually increase from 0 to infinity when connected. probes (this is a sign of serviceability). If the resistance remains zero, the capacitor is broken.

Why does the compressor hum but does not start?

This is a typical symptom of a faulty starting circuit. The reasons may be as follows:

1. Open winding. (resistance S → C = ∞).
2. Faulty starting relay (does not close the contacts when starting).
3. Capacitor breakdown (capacity below 20% of the nominal value).
4. Compressor shaft jamming (mechanical blocking).

Start diagnostics by checking the resistance of the windings and capacitor.

What is the difference between the starting winding and the working winding?

Main differences:

Parameter	Starting winding	Working winding
Resistance	12–20 Ohm	5–10 Ohm
Current	High (2–3 times higher than nominal)	Nominal (0.5–1.5 A)
Operating time	1–3 seconds (only at startup)	Permanently
Connection	Via the starting relay	Directly to the network

Is it possible to rewind the compressor winding yourself?

Theoretically, yes, but in practice it is difficult to implement at home. For rewinding you need:

• A special winding machine.
• Copper wire of the same cross-section (data taken from the compressor data sheet).
• Varnish for impregnating the windings. (for example, ML-92).
• Oven for drying (temperature 120–150°C).

Without experience, there is a high risk of getting a winding with incorrect resistance or interturn short circuit. In most cases, it is cheaper to buy a used compressor for disassembly.